The first thing you would need, is a lot of time! Managing a VTC takes up almost all of your own time, even with a large team behind you!
If you're happy with that, then you need to find a way to make your VTC stand out from the rest. Often the best way to do this is by having a high quality, unique skin & if possible, other mods such as trailers, that no other VTC has.
The final thing I would say is that you need to have patience if your VTC isn't successful at first! The VTC I'm working for at the moment was very small when it first opened, but in the year or so, we've gained experienced modders, and drivers who are willing to work hard, and now have 190+ drivers!
I hope this helps you, and if you have any more questions, feel free to drop me a PM!